Semiconductor device operating in high frequency range

ABSTRACT

A semiconductor device operating in a high frequency range is formed in a structure capable of facilitating and highly accurate frequency characteristic test. A semiconductor substrate (1) is provided on a major surface with an input electrode pad (2a) and an output electrode pad (2b) to be connected with integrated circuits included in the semiconductor substrate (1) respectively, while grounding electrode pads (2c) are formed each with paired grounding lines disposed on both sides of the input and output electrode pads (2a, 2b), respectively, to sandwich the same. The grounding electrode pads (2c) ground the semiconductor substrate (1) in a high frequency characteristic test. The input electrode pad (2a) and the grounding lines of the grounding electrode pads (2c) on both sides thereof as well as the output electrode pad (2b) and the corresponding grounding lines of the grounding electrode pads (2c) on both sides thereof are positioned to be placed in contact with a probing needle of a well-known high frequency wafer probe during a high frequency characteristic test.

This is a division of application Ser. No. 081,709, filed Aug. 3, 1987,now U.S. Pat. No. 4,926,234, issued May 15, 1990.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor device and, moreparticularly, it relates to a semiconductor device operating in a highfrequency range exceeding several tens MHz.

2. Description of the Prior Art

A semiconductor device operating in a high frequency range is dividedinto a plurality of IC chips from a wafer after manufacturing, to besubjected to a high frequency characteristic test. Description isprovided of a conventional method of measuring such high frequencycharacteristic with reference to FIGS. 1-3.

FIG. 1 is a plan view showing an example of a conventional highfrequency IC chip, and FIG. 2 is a sectional view taken along the line2--2 in FIG. 1.

An input electrode pad 2a and an output electrode pad 2b are formed onan IC chip 1 including circuits of various functions, to be inconduction with the respective circuits. A grounding metal member 4 isformed on the rear surface of the IC chip 1, to be in conduction withthe front surface of the IC chip 1 through a viahole 3. As shown in FIG.2, the input electrode pad 2a and output electrode pad 2b (not shown)are formed by microstriplines.

FIG. 3 is a plan view showing the device of FIG. 1 in a state ofmeasuring the high frequency characteristic of the IC chip 1 thusformed.

In general, a plurality of such IC chips 1 are independently received ina chip carrier 6 to be in conduction with the exterior through a jig 5,which is adapted to measure the high frequency characteristic of the ICchips 1. Several hours are required to prepare for such measurementsince the plurality of IC chips 1 are respectively obtained from thewafer and the chip carrier 6 is prepared in response to the chip sizefor receiving the IC chips 1, to be set in the measuring jig 5. Further,accuracy in measurement is reduced through parasitic capacitance of thejig 5 itself and resonance by the jig 5.

On the other hand, there has been developed a high frequency waferprobe, which can measure the high frequency characteristic throughcontact with a single surface of the measured object.

Such a probe is disclosed in "Precise MMIC Parameters Yielded by 18˜GHzWafer Probe", by K. R. Greason et al., Microwave System News, issued onMay 1983, with reference to a basic method of microwave on-waferprobing.

Such a probe is also disclosed in "Microwave Wafer Probing AchievesOn-Wafer Measurements Through 18 GHz" by D. E. Carlton et al., MicrowaveSystem News, issued on May, 1985, with reference to a calibration methodin microwave on-wafer probing (particularly loss correction, crosstalkcorrection, etc., in a two-port device).

However, it is difficult to achieve on-wafer measurement of asemiconductor device through such a probe.

Since the surface of an IC chip provided with input and output electrodepads is entirely covered by a nitride film except for the parts of theinput and output electrode pads, grounding lines must be extracted froma grounding metal member provided on the rear surface of the IC chip.However, measurement through the probe is performed by placing the ICchip on a stage, and hence it is difficult to bring the needle of theprobe into contact with the rear surface of the IC chip.

SUMMARY OF THE INVENTION

The principal object of the present invention is to provide asemiconductor device whose high frequency characteristic can be measuredin a short time with high accuracy.

In order to achieve the above object, the semiconductor device accordingto the present invention comprises an IC chip provided on a surface withan input electrode pad and an output electrode pad and groundingelectrode pads formed on said surface of the IC chip to sandwich theinput and output electrode pads at regular intervals.

The semiconductor device of such structure facilitates measurement ofthe high frequency characteristic on a single surface thereof throughthe aforementioned high frequency wafer probe.

Further to the above description, an important first feature of thepresent invention is in that the grounding electrode pads are providedon the surface of the IC chip and the second feature is in that thegrounding electrode pads are provided in positions separable by cutting,and a third feature is in that the distance between the input electrodepad and the grounding electrode pads is constant and equal to thatbetween the output electrode pad and the grounding electrode pads.

By virtue of such constant and equal spaces provided between the pads,the same probe can be employed for various types of IC chips regardlessof difference in size.

These and other objects, features, aspects and advantages of the presentinvention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing an example of a conventional highfrequency IC chip, which is provided with an input electrode pad and anoutput electrode pad on its surface;

FIG. 2 is a sectional view taken along the line 2--2 in FIG. 1;

FIG. 3 is a plan view showing the device of FIG. 1 in a state ofmeasuring the high frequency characteristic of a conventional IC chip,which is received in a chip carrier to be set in a measuring jig;

FIG. 4 is a plan view of a high frequency IC chip according to anembodiment of the present invention, which is formed on its surface withgrounding electrode pads on both sides of the input and output electrodepads respectively;

FIG. 5 is a sectional view taken along the line 5--5 in FIG. 4;

FIG. 6 is a partially fragmented perspective view showing a highfrequency wafer probe employed in the embodiment of the presentinvention, which probe is in coplanar line structure provided withgrounding lines and a signal line on its lower surface;

FIG. 7 is a partially fragmented perspective view showing a preferredembodiment of this invention in a state of measuring the high frequencycharacteristic of the IC chip in which the grounding lines and thesignal line of the probe are in contact with the grounding electrodepads and the input electrode pad of the IC chip; and

FIG. 8 is a plan view showing the device in a state following of cuttingoff of unnecessary parts of the IC chip according to the presentinvention after measurement of the high frequency characteristic, inwhich the input and output electrode pads are partially cut with thegrounding electrode pads to be separated from the IC chip.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 4 is a plan view showing a semiconductor device according to anembodiment of the present invention, and FIG. 5 is a sectional viewtaken along the line 5--5 in FIG. 4.

With reference to FIGS. 4 and 5, description is now provided of thestructure of the semiconductor device according to the presentinvention.

An IC chip 1 serving as a semiconductor substrate assembled withcircuits having various functions is provided at a surface thereof withan input electrode pad 2a and an output electrode pad 2b, which are inconduction with the respective circuits. Pairs of grounding electrodepads 2c are formed on both sides of the input electrode pad 2a andoutput electrode pad 2b respectively, to each be connected with agrounding metal member 4 provided on the rear surface of the IC chip 1through an opening passing through the IC chip 1, i.e., a viahole 3.Thus, the IC chip 1 of the present invention is implemented by aconventional IC chip, which has grounding electrode pads provided onboth sides of input and output electrode pads respectively to sandwichthe same.

FIG. 6 is a partially fragmented perspective view showing the forwardend portion of a probing needle of a well-known high frequency waferprobe, and FIG. 7 is a partially fragmented perspective view showing astate of measuring the high frequency characteristic of the IC chipaccording to the present invention by the probe.

Referring to FIGS. 6 and 7, the forward end portion of the probingneedle of the probe is in coplanar line structure, which is formed by aceramic body 7 provided on its bottom surface with grounding lines 8aand 8c and asignal line 8b. In general, the distance between thegrounding line 8a and the signal line 8b is constant and equal to thatbetween the grounding line 8c and the signal line 8b. Therefore, even ifIC chips 1 are varied in size, measurement of the high frequencycharacteristic can be easily achieved by conforming a positionalrelationship between the input electrode pad 2a and output electrode pad2b and the grounding electrode pads 2c on each IC chip to the positionalrelationship between the respective lines on the probe to be employed.It may be obvious for those skilled in the art to form the respectivepads on prescribed positions of the IC chip 1.

Thus, high frequency wafer probing can be extremely quickly performed bysimply bringing the forward end portion of the probing needle into closecontact with the input and output parts of the IC chip 1 as indicated inFIG. 7. Since the grounding electrode pads 2c are provided on thesurface of the IC chip 1, the probe can be effected on a single surfaceof the IC chip 1, which is not yet divided but is still in a wafer stateplaced on astage.

As a result, the time required for measuring the high frequencycharacteristic of the semiconductor device according to the presentinvention will be reduced to about 1/100 as compared with theconventionalcase. Further, accuracy in measurement of the high frequencycharacteristicof the semiconductor device according to the presentinvention will be improved by about 10 times as compared with theconventional case. The semiconductor device according to the presentinvention requires no measuring jig 5 as employed in the conventionalcase, (see FIG. 3) wherebyno influence by the parasitic capacitance ofsuch a jig or resonance by such a jig is exerted on any measurements.

FIG. 8 shows a state of the IC chip 1 following cutting of the pad partsemployed in measurement of the high frequency characteristic to leaveonlya required part of the IC chip 1 separated from the wafer after themeasurement. As a matter of course, it is also possible to use the ICchip1 in the state as shown in FIG. 4 without separating the pad partsemployedfor the measurement.

As illustrated in FIGS. 4, 7 and 8, the grounding electrode pads 2c arelocated away from the integrated circuits formed on the substrate. Thisnot only facilitates separation of the grounding electrode pads 2c aftertesting, if desired, but also ensures that they are effectively isolatedfrom the integrated circuits if left in place.

Although the grounding electrode pads 2c are adapted to sandwich theinput electrode pad 2a and output electrode pad 2b in the aforementionedembodiment, such grounding electrode pads may be provided in a differentmanner so long as the positional relationship of the same can conform tothat of the respective lines on the forward end portion of the probingneedle in the probe employed for measurement of the high frequencycharacteristic.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

What is claimed is:
 1. A semiconductor device operating in a highfrequency range, comprising:a semiconductor substrate having a firstmajor surface and including integrated circuits mounted thereon; inputelectrode pad means formed on said major surface of said semiconductorsubstrate and connected with said integrated circuits; output electrodepad means formed on said major surface of said semiconductor substrateand connected with said integrated circuits; and grounding electrode padmeans formed on said major surface of said semiconductor substrate,adjacent to said input electrode pad means and said output electrode padmeans, for grounding said semiconductor substrate in a high frequencycharacteristic test, said grounding electrode pad being located awayfrom said integrated circuits so as to be isolated therefrom.
 2. Asemiconductor device operating in a high frequency range, comprising:asemiconductor substrate having a first major surface and a second majorsurface, integrated circuits mounted on said first major surface andopenings passing between said first and second major surfaces throughthe semiconductor substrate; an input electrode pad formed on said firstmajor surface of said semiconductor substrate and connected with saidintegrated circuits; an output electrode pad formed on said first majorsurface of said semiconductor substrate for grounding said semiconductorsubstrate in a high frequency characteristic test; and groundingelectrode pads formed on said first major surface of said semiconductorsubstrate, adjacent to said input electrode pad and said outputelectrode pad, to be in conduction with a grounding metal member throughsaid openings, said grounding electrode pad being located away from saidintegrated circuits so as to be isolated therefrom.